414 AMERICAN HYMENOPTERA. 



labrum broadly outcurved , the translucent areas usually only very faintly 

 visible and often entirely absent. Malar space somewhat longer than 

 its width at the apex, about one-fourth as long as the eye. Ocelli 

 placed much below the supra-orbital line, in the narrowest part of the 

 vertex. Flagellumof antenna somewhat less than twice as long as the 

 scape ; third antennal segment fully as long as the fourth and fifth 

 taken together, the fifth slightly longer than the fourth. 



Thorax. — Anterior part of dorsum covered with yellow pile ; the 

 region between the bases of the wings always black ; the scutellum 

 very rarely entirely black, more often entirely covered with yellow 

 pile, but usually bearing a mixture of yellow and black pile, at least 

 on the hind portion ; the center of the disc naked. Mesopleura with 

 yellow pile extending down some distance below the level of the bases 

 of the wings, but their lower two-thirds black ; metapleura and sides 

 of the median segment entirely black ; extreme sides of the metanotum 

 sometimes with tufts of yellow pile (behind the bases of the hind 

 wings) . 



Abdomen. — Dorsum : segment one black, but very often with some 

 yellow pile on the hind corners ; segments two and three yellow, but 

 often with a small amount of black pile on the basal middle of the 

 second ; segments four, five and six black. Venter black. Hypopy- 

 gium without a median carina. 



Wings. — Very dark and with slight violaceous reflections. 



Legs. — Black and with black corbicular fringes. 



Worker. — Much like the queen. 



Male. Head. — Face with considerable yellow pile above and below 

 the bases of the antennae and often with a faint sprinkling of it on the 

 sides of the clypeus ; occiput largely covered with yellow pile, this 

 extending forward almost to the ocelli ; cheeks often entirely black, 

 but as often with considerable yellow pile connecting with the yellow 

 on the occiput. Malar space about one-half as long as its width at 

 apex. Clypeus mostly bare of pile except on the sides and base. The 

 ocelli situated nearly half-way from the supra-orbital line to the bases 

 of the antennae, the lateral ones almost touching the margins of the 

 eyes. 



Thorax. — Dorsum usually yellow with a poorly defined black inter- 

 alar band, but often with only a black spot on the disc and occasion- 

 ally with only yellow pile ; the center of the disc more or less bare. 

 Mesopleura covered with yellow pile to, or very nearly to, the bases of 

 the legs. The metapleura with lower portions dark and upper por- 

 tions bearing yellow pile. The extreme sides of the metanotum with 

 yellow pile (behind the bases of the hind wings). The sides of the 

 median segment usually dark, but occasionally with some light pile. 



Abdomen. — Dorsum : segment one usually covered with yellow pile, 

 but often more or less black in the middle and in front, and rarely 



